该系列（Spring Cloud学习案例）博客,是博主在学习周立先生《Spring Cloud与Docker微服务架构实战》一书时，将其中的案例部分，整理出来，并做一些细小的改动，添加一些自己的元素，记录下详细的步骤。
因为是案例分享，过多的理论知识不再赘述，只着重实战的过程。
第一个案例是关于一个简单的服务提供者和消费者，这个案例主要是让大家简历微服务的概念。
案例说明
用户通过客户端发起购票请求,首先发送给电影微服务,电影微服务需要知晓该用户的信息,又发送请求到用户微服务.关系如下:
案例分析
用户微服务:服务提供者,提供根据id查询用户信息.使用mybatis完成.
电影微服务:服务消费者,接受用户请求中的id参数,调用用户微服务提供的根据id查询用户信息的服务.使用restTemplate进行rest调用.
案例实现
1. 服务提供者
第一步:创建maven项目
第二步:编写pom.xml
该服务使用mybatis作为dao层框架，使用druid作为连接池，使用mysql数据库。
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.cgg.springcloud</groupId>
<artifactId>demo01-user-provider</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo01-user-provider</name>
<description>服务提供者:用户微服务</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Edgware.SR3</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<!-- springboot 整合 web开发 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- springboot 整合 druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.9</version>
</dependency>
<!-- springboot 整合 mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- springboot 整合 mybatis -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
</dependencies>
</project>
第三步:数据库准备
- 创建数据表t_user
CREATETABLE `t_user` ( `id` bigint(20) unsigned NOTNULL AUTO_INCREMENT, `username` varchar(32)NOTNULL, `name` varchar(32)NOTNULL, `age` int(3)NOTNULL, `balance` decimal(10,2)NOTNULL, PRIMARYKEY(`id`) ) ENGINE=InnoDBAUTO_INCREMENT=4DEFAULT CHARSET=utf8;
- 插入三条测试数据
INSERTINTO `t_user` VALUES(1,'damo','达摩',20,100.00); INSERTINTO `t_user` VALUES(2,'mulan','花木兰',22,100.00); INSERTINTO `t_user` VALUES(3,'daxiaojie','孙尚香',18,100.00);
第四步:配置数据源
在resources中创建application.yml文件。创建properties文件也行。
server:
port: 9001
#==================================
# 数据源配置
# ==================================
spring:
datasource:
druid:
url: jdbc:mysql:///springcloud
username: root
password: root
第五步:准备实体
package com.cgg.springcloud.demo1.pojo;
publicclass User {
private Long id;
private String username;
private String name;
private Integer age;
private Double balance;
public Long getId() {
returnid;
}
publicvoid setId(Long id) {
this.id = id;
}
public String getUsername() {
returnusername;
}
publicvoid setUsername(String username) {
this.username = username;
}
public String getName() {
returnname;
}
publicvoid setName(String name) {
this.name = name;
}
public Integer getAge() {
returnage;
}
publicvoid setAge(Integer age) {
this.age = age;
}
public Double getBalance() {
returnbalance;
}
publicvoid setBalance(Double balance) {
this.balance = balance;
}
}
第六步:DAO层编写
- mapper接口
package com.cgg.springcloud.demo01.mapper;
importcom.cgg.springcloud.demo01.pojo.User;
publicinterface UserMapper {
// 根据id查询用户信息
UserselectUserById(Long id);
}
- UserMapper.xml文件
<?xml version="1.0"encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTDMapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cgg.springcloud.demo01.mapper.UserMapper">
<!-- 根据id查询用户信息 -->
<select id="selectUserById"parameterType="long" resultType="com.cgg.springcloud.demo01.pojo.User">
select*
fromt_user
whereid = #{id}
</select>
</mapper>
第七步:Service层编写
- 接口
package com.cgg.springcloud.demo01.service;
importcom.cgg.springcloud.demo01.pojo.User;
publicinterface UserService {
// 根据id查询用户信息
UserselectUserById(Long id);
}
- 实现类
packagecom.cgg.springcloud.demo01.service.impl;
importorg.springframework.beans.factory.annotation.Autowired;
importorg.springframework.stereotype.Service;
importorg.springframework.transaction.annotation.Transactional;
importcom.cgg.springcloud.demo01.mapper.UserMapper;
import com.cgg.springcloud.demo01.pojo.User;
importcom.cgg.springcloud.demo01.service.UserService;
@Service
@Transactional
publicclass UserServiceImpl implements UserService{
@Autowired
private UserMapper userMapper;
@Override
public User selectUserById(Long id) {
returnuserMapper.selectUserById(id);
}
}
第八步:Controller层编写
packagecom.cgg.springcloud.demo01.controller;
importorg.springframework.beans.factory.annotation.Autowired;
importorg.springframework.web.bind.annotation.PathVariable;
importorg.springframework.web.bind.annotation.RequestMapping;
importorg.springframework.web.bind.annotation.RequestMethod;
importorg.springframework.web.bind.annotation.RestController;
importcom.cgg.springcloud.demo01.pojo.User;
import com.cgg.springcloud.demo01.service.UserService;
@RestController
@RequestMapping("/user")
publicclass UserController {
@Autowired
private UserService userService;
@RequestMapping(value = "/{id}", method = RequestMethod.GET)
public User selectUserById(@PathVariable Long id){
returnuserService.selectUserById(id);
}
}
第九步:启动类编写
注意需要进行mapper接口的自动扫描
package com.cgg.springcloud.demo01;
importorg.mybatis.spring.annotation.MapperScan;
importorg.springframework.boot.SpringApplication;
importorg.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.cgg.springcloud.demo01.mapper")
publicclass UserProviderApplication {
publicstaticvoid main(String[] args) throws Exception {
SpringApplication.run(UserProviderApplication.class, args);
}
}
第十步:测试
测试url:localhost:9001/user/1
2. 服务消费者
第一步:创建maven项目
第二步:编写pom.xml
因为电影微服务只是简单的使用restTemplate调用用户微服务的接口.所以只需添加springboot整合web开发的依赖即可.
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>cn.cgg.springcloud</groupId>
<artifactId>demo01-movie-consumer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo01-movie-consumer</name>
<description>服务消费者:电影微服务</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Edgware.SR3</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<!-- springboot 整合 web开发 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
第三步:创建用户实体
消费者中的用户实体跟提供者的用户实体一致.在实际开发中,一般将pojo单独作为一个工程,打成jar,供其他项目依赖.
package com.cgg.springcloud.demo01.pojo;
public class User {
private Long id;
private String username;
private String name;
private Integer age;
private Double balance;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Double getBalance() {
return balance;
}
public void setBalance(Double balance) {
this.balance = balance;
}
}
第四步:编写启动类
因为启动类也是一个配置类. @SpringBootApplication是一个组合注解.在启动类中注册restTemplate的实例.
package com.cgg.springcloud.demo01;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
public class MovieConsumerApplication {
// 在spring容器中注册restTemplate
@Bean(name = "restTemplate")
public RestTemplate getRestTemplate(){
return new RestTemplate();
}
public static void main(String[] args) throws Exception {
SpringApplication.run(MovieConsumerApplication.class, args);
}
}
第五步:编写controller
使用restTemplate调用提供者的接口.
package com.cgg.springcloud.demo01.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import com.cgg.springcloud.demo01.pojo.User;
@RestController
@RequestMapping("/movie")
public class MovieController {
private static final String GET_USERINFO = "http://localhost:9001/user/";
@Autowired
private RestTemplate restTemplate;
@GetMapping("/user/{id}")
public User getUserInfo(@PathVariable Long id){
return restTemplate.getForObject(GET_USERINFO + id, User.class);
}
}
第六步:配置application.yml
在resources下创建application.yml文件。配置项目启动端口.跟提供者区分开。
server: port: 9002
第七步:测试
测试url:http://localhost:9002/movie/user/1
Spring Cloud的第一个学习案例就写完了，通过这个案例，大家主要理解微服务的基本思想。
案例github源码：https://github.com/xiecheng310/springcloud
https://github.com/xiecheng310/springcloud.git
https://github.com/xiecheng310/springcloud.git